How to exchange titles?

[Habberdashery]

Is there a way to switch titles between generals without the loss of loyalty traits?
Also, are ancillaries such as Lord High Marshall and Lord High Chancellor transferable?

[Duck of Death]

If you mean titles like "the Great" or "the Silver Tongued", youd have to go into the files to change how such titles are given out, but they cant just be manually passed from one general to another.
The same goes for the specific ancillaries you mentioned... but some other ancillaries can be freely passed from one general to another just by having both generals in the same army outside of a town.
Simply drag and drop the ancillary from one to the other (there's an 8 ancillary max per general).
I also believe any ancillary can be given or removed from a general by using the '~' key and typing "give/remove ancillary this (make sure you have clicked on your general) crown_england (for example)